Year	Percent
1965	23.09746
1966	24.35597
1967	28.44037
1968	26.07781
1969	28.9181
1970	24.11576
1971	18.66406
1972	20.66257
1973	22.16819
1974	13.84212
1975	26.0109
1976	32.55463
1977	43.44284
1978	39.86586
1979	28.81663
1980	34.29789
1981	38.47805
1982	52.36386
1983	49.35217
1984	44.64112
1985	42.74458
1986	48.01252
1987	37.12301
1988	42.93979
1989	41.36975
1990	58.07205
1991	125.71092
1992	54.2178
1993	44.28585
1994	42.33063
1995	41.9645
1996	39.18637
1997	39.59159
1998	51.09332
1999	39.4368
2000	30.14693
2001	35.53874
2002	36.60915
2003	34.46415
2004	32.37997
2005	28.26686
2006	24.16695
2007	28.31712
2008	25.92378
2009	29.39497
2010	30.35451
2011	25.89881
2012	26.2796
2013	26.74517
2014	31.5308
2015	44.93449
2016	46.42906